JP2651925B2 - Disk drive motor incorporated from one side of the disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive motor that can be incorporated from one side of a magnetic disk drive used for recording and reproducing data on a magnetic disk, for example.

2. Description of the Related Art Conventionally, when a magnetic disk drive motor (hereinafter, simply referred to as a "motor") is incorporated into a magnetic disk drive, it is common practice to mount a pre-assembled motor on the magnetic disk drive. Mounting on the base. However, this has problems such as an increase in the thickness of the entire apparatus and an increase in the number of parts.

Therefore, as shown in FIG. 11, the motor 10 is also directly incorporated into the base 11 of the magnetic disk drive A.

The structure and the assembling sequence will be described. A hollow fixed shaft which is press-fitted in advance into a hollow shaft 12 integrally formed by projecting from the inner and outer surfaces 11a and 11b of the service base of the magnetic disk drive A and the motor 10 is formed.
At 13, the iron core 15 of the stator assembly 16 including the iron core 14 and the armature coil 15 is first mounted on the hollow fixed shaft 13 by press-fitting or bonding, and the retaining ring 17 is assembled.

Next, a spring 18 and a bearing 19 are sequentially inserted below the retaining ring 17.

The rotor assembly 24 includes a shaft 20, a rotor 22 integrally attached to a lower end (a lower end side in FIG. 11) of the shaft 20 via a flange 21, and a magnet 23 on an inner surface of the rotor 22. Shaft 20 with hollow fixed shaft
13 is inserted from below into the spring 18 against the spring 18.

Next, the bearing 25 is inserted from the upper end of the shaft 20, and the retaining ring 26 is engaged with the shaft 20. Therefore, the position of the shaft 20, which is urged downward by the spring 18 via the bear rig 19 and the flange 21, is such that the retaining ring 26 is a bearing.
25 is pressed against the retaining ring 17 and determined.

Finally, after attaching a magnetic fluid seal 27 to the upper end of the shaft 20 and the hollow fixed shaft 13, a disk hub 28 is press-fitted into the tip of the shaft 20.

To mount the magnetic disk B on the motor 10, the spacers S are alternately interposed and inserted into the disk hub 28, and then the clamper 29 is detachable from the disk hub 28.
Is performed by tightening.

However, with such a structure, the outer surface of the base 11
After the stator assembly 16 and the rotor assembly 14 are assembled with the 11b facing upward, the large base 11 is turned over, and the bearing 25, the magnetic fluid seal 27, the disk hub 18 and the like must be assembled with the inner surface 11a facing upward. Without
For the assembling, an inside-out process is necessary, which hinders the assembling work, resulting in poor productivity and a large number of parts.

Means for Solving the Problems The present invention provides a center axis protruding inward from an inner surface of a base of a disk device, an armature concentrically disposed with respect to the center axis, and a free end of the center axis. A cup-shaped rotor frame rotatably supported by a pair of rolling bearings by a pair of rolling bearings and having a cylindrical side wall and a disk receiving portion surrounding the outer periphery of the armature; and the armature fixed to the inner surface of the cylindrical side wall. The above-mentioned problem is solved by a disk drive motor which is provided with an outer peripheral surface and a permanent magnet facing each other via a gap, and is incorporated from one side of the disk device.

Action The motor of the present invention is assembled by first turning the inner surface of the base up and turning it up, and then assembling the components sequentially around the central axis.

The disk is inserted into the outer periphery of the cylindrical side wall of the rotor frame, received by the disk receiving portion, and attached to the motor.

When the central axis is press-fitted, the central axis protrudes from the base by press-fitting.

Accordingly, since the components of the motor are sequentially assembled with the central axis facing upward, there is no need to turn the base over and the number of components is reduced. Further, the base line of the armature is drawn out of the base from near the base of the central axis.

Embodiment FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a motor 40 for driving a magnetic disk.

A central shaft 42 is integrally formed with an inner surface 41a of a base 41 shared by the magnetic disk device A and the motor 40 so as to protrude inward. The central shaft 42 has a lower portion serving as a large-diameter portion 42a, an intermediate portion serving as a middle-diameter portion 42b, and a leading end serving as a small-diameter portion 42c.

The armature 43 is arranged concentrically on the center axis 42 and has a laminated core 44
And a coil 45. A laminated iron core 44 is attached to the middle diameter portion 42b of the center shaft 42 by press fitting or bonding in contact with the large diameter portion 42a. A lead wire 47 connected to the coil 45 via a printed circuit board 46 has a hole 48 formed in the base 41.
From the outside.

A pair of bearings (rolling bearings) 49, 50 are attached to the small diameter portion 42c of the central shaft 42 by press-fitting the inner rings 49b, 50b together with an adhesive. Inner ring 49 of bearing 49
b is in contact with the step portion of the small diameter portion 42c and the middle diameter portion 42b. The bearing 49 and the bearing 50 are separated from each other.

The rotor 60 rotates with respect to the armature 43, and includes a rotor frame 61 and a permanent magnet 68.

A rotor frame 61 made of steel or a composite of steel and aluminum has a shape in which a cup-shaped one is turned down as a whole, and a bearing 49 is provided in a large-diameter center hole 63 of a thick portion 62 corresponding to the bottom thereof. Outer ring 49a is press-fitted together with an adhesive. An outer ring 50a of the bearing 50 is fitted in the small-diameter center hole 64 with a gap. Disc springs 65 combined in series are compressed and interposed between the outer rings 49a and 50a of the bearings 49 and 50 with an appropriate preload. Therefore, the disc spring 65 is
By expanding the distance between the outer races 49a and 50a in the axial direction, the backlash in the axial and radial directions of the bearings 49 and 50 is eliminated, and a preload is applied.

In the thick portion 62, a cylindrical side wall 66 having a uniform outer diameter covering the outer peripheral surface of the iron core 44 is formed so as to extend. Its tip faces an annular projection 67 formed on the base 41. Side wall 66
An annular permanent magnet 68 facing the iron core 44 with an air gap C is press-fitted into the inner surface 66a of the magnet. A magnetic disk receiving portion 69 protruding outward is formed in a flange shape on the outer surface 66b of the side wall 66. The receiving portion 69 has a receiving surface 69a formed as a plane perpendicular to the central axis.

The center hole of the magnetic disk B is
66b are inserted and stacked at predetermined intervals on the disk receiving portion 69 via the spacer S, and are fixed by the holding metal fitting 72 and the screw 73.

As shown in FIG. 2, the armature 43 is energized so that the coil 45 is wound in a slot 70 provided in the iron core 44 to generate a rotating magnetic field having the same number of magnetic poles as the permanent magnet 68. The rotor 60 is rotated in the same direction as the rotating magnetic field. At the time of this rotation, the rotor frame 61 is moved to the center axis 4 by the bear rigs 49 and 50.
The second free end 42d is supported with high rigidity, and the thick portion 62 extends from the side wall 66, the permanent magnet 68, the disk receiving portion 69, and the rotating portion such as the magnetic disk B fixed on the receiving portion 69. Is firmly supported, so that accurate rotation can be achieved without rotational shake.

 Next, the order of assembling the motor 40 having the above configuration will be described.

First, the inner surface 41a of the base 41 is turned up and the center axis 42 is turned up. Next, the laminated iron core 44 of the armature 43 is attached to the central shaft 42 by press-fitting or bonding. At this time, the lead wire 47 is drawn out of the base 41 from the hole 48.

Next, the rotor frame 61 in which the bearing 49 is press-fitted into the large-diameter center hole 63 in advance is inserted into the center shaft 42, and the bearing 49 is
Into the small-diameter portion 42c such that the inner ring 49b comes into contact with the step of the middle-diameter portion 42b. Thereafter, a disc spring 65 is inserted into the center shaft 42, the inner ring 50b of the bearing 50 is pressed into the small diameter portion 42c, and the outer ring
50a is fitted into the small-diameter center hole 64 of the rotor frame 61 by a clearance fit. Finally, the gap is fixed with an adhesive, and the cover 74 is incorporated into the small-diameter center hole 64 so as to cover the side surface of the bear rig 50.

In order to mount the magnetic disk B on the motor 40 assembled in this manner, the magnetic disk B is inserted into the rotor frame 61 with the spaces S interposed alternately, and is integrated with the rotor frame 61 by the holding metal fitting 72 by tightening the screw 73.

FIG. 3 and FIG. 4, which is a partially enlarged view of FIG. 3, are longitudinal sectional views of the second embodiment. Only the structural parts different from those of FIG. I will explain.

This embodiment differs from the case of FIG. 1 in the shape of the central shaft and the structure for applying the preload of the bearing.

The center shaft 102 of the magnetic disk drive motor 100 is formed integrally with the inner surface 101a of the base 101 of the magnetic disk device A, and has a uniform outer diameter. Central axis between base 101 and armature 43 and between armature 43 and bearing 49
Rings 103 and 104 are fitted on 102 respectively.

Next, in this structure, the magnetic disk drive motor
The assembly sequence of 100 will be described.

First, the ring 103 is fitted into the center shaft 102, the armature 43 is press-fitted, and the ring 104 is inserted.

Then, one of the bearings 49 or 50 is inserted into the center hole 106 of the rotor frame 61 to which the annular permanent magnet 68 is attached in advance.
After the outer ring 49a or 50a is press-fitted or attached with an adhesive, a cylindrical spacer 105 is inserted.
The outer ring of the other bearing 49 or 50 so that 05 intervenes
Press-fit or attach 49a or 50a with adhesive. After that, the bearings 49, 50 are inserted into the central shaft 102, and as shown in FIG.
0b is bonded and fixed to the center shaft 102.

When the external force F is applied, as shown in FIG.
49a and 50a are moved in a direction away from each other, and a preload is applied.

The spacer 105 may be formed integrally with the inner periphery of the center hole 106 of the rotor frame 61.

In the embodiment of FIG. 3, the spacer 105 is used in place of the disc spring 65 of FIG. 1, so that the structure is simplified and the space between the bearings 49 and 50 can be reduced.

Next, the embodiment shown in FIG.
5 is omitted, and the structure for applying a preload to the bearing is further simplified.

The assembling order in this structure is substantially the same as in the second embodiment.

That is, first, the ring 103 is inserted into the center shaft 102, and the armature
43 is press-fitted, and the ring 104 is inserted. Then, the outer rings 49a, 50a of the two bearings 49, 50 are attached to the center hole 106 of the rotor frame 61, to which the annular permanent magnet 68 has been attached in advance, at a proper interval, by press-fitting or using an adhesive. After that, insert the bearings 49 and 50 into the central shaft 102,
As shown in FIG. 5, the inner races 40b, 50b are bonded and fixed to the center shaft 102 while the external force F is applied to the inner race 50b.

When the external force F is applied, as shown in FIG.
49a and 50a are moved in a direction away from each other, and a preload is applied.

The structure shown in FIG. 5 can be applied to the drive motor 40 shown in FIG.

FIG. 6 is a longitudinal sectional view of the third embodiment, in which the same reference numerals as in FIG. 1 indicate the same structural parts, and only the structural parts different from those in FIG. The description will be made with reference to FIG.

The third embodiment differs from the first embodiment in the structure of the central axis.

The central shaft 82 of the magnetic disk drive motor 80 is press-fitted into a press-fitting hole 83a of a hollow press-fitting portion 83 integrally projecting from the inner surface 81a of the base 81 of the magnetic disk drive A.

In this structure, to assemble the magnetic disk drive motor 80, first, the inner surface 81a of the base 81 of the magnetic disk device A is turned up, and the press-fit portion 83 is turned up. The central shaft 82 is press-fitted into the press-fit hole 83a of the press-fit portion 83 to be integrated with the press-fit portion 83.

Then, the laminated core 44 is attached to the outer periphery 83b of the press-fit portion 83 by press-fitting or bonding, and the bearing 4 is attached to the central shaft 82.
Assemble the rotor frame 61 via 9,50.

FIG. 7 is a longitudinal sectional view of the fourth embodiment. The difference from the embodiment of FIG. 6 is that the central shaft 92 of the magnetic disk drive motor 90 is a stepped shaft of a thin shaft portion 92a and a thick shaft portion 92b. The thin shaft portion 92a of the central shaft 92 is press-fitted into a press-fit hole 93a of a hollow press-fit portion 93 protruding from the inner surface 91a of the base 91.

In this structure, as in the embodiment of FIG.
The laminated core 44 is provided on the outer periphery 93b of the 93, and the bearing 49 is provided on the central shaft 92.
The rotor frame 61 is attached via 50.

In the embodiment of FIGS. 6 and 7, a spacer may be interposed between the bearings 49 and 50 instead of the disc spring as shown in FIGS. Further, as shown in FIG. 5, a structure in which the disc spring and the spacer are omitted may be employed.

8 and FIG. 9, which is a partially enlarged view of FIG. 8, show a fifth embodiment in which the center axis 112 of the magnetic disk drive motor 110 is a thin shaft portion 112a and a thick shaft portion 112b, A thin shaft portion 112a is inserted into the press-fit hole 113a of the hollow press-fit portion 113 protruding from the inner surface 111a.
Press fit, the outer diameter of the outer periphery 113b of the press fit portion 113, and the thick shaft portion 112b
Have the same outer diameter. Furthermore, bearings 119 and 120 without an inner ring are used, and a spacer 125 is interposed between the bearings 119 and 120.

The assembling sequence in this structure is such that the bearings 119 and 120 are pre-installed on the free end 112d of the center shaft 112 and the spacer 125
Is press-fitted into the center hole 113a of the press-fit portion 113 into which the armature 43 is press-fitted. Then, the outer ring 119 of the bearing
The rotor frame 61 is fixed to a and 120a by an adhesive or press fitting.

In this structure, in addition to the above assembly order, there is also the following assembly order.

First, the spacer 125 is inserted between the bearings 119 and 120 incorporated in the center shaft 112. After that, the rotor frame 6
1, the bearings 119 and 120 are attached by press-fitting or an adhesive, and the central shaft 112, the bearings 119 and 120, and the rotor frame 61 are integrated. Finally, the center shaft 112 is connected to the armature 4
3 is press-fitted into the central hole 113a of the press-fitting portion 113 which is attached in advance and integrated.

In this case, the spacer 125 has a C-shape in plan view, and its length error is controlled to 1 μm or less.

Also in this structure, a preload can be applied to the bearing as in FIG.

Finally, the magnetic disk drive motor 130 in FIG.
In the sixth embodiment, the armature 43 is press-fitted into an annular protruding wall 135 formed on the base 131 so as to surround the lower bearing 49 in order to reduce the thickness of the entire device A of the magnetic disk. .

The rotor 140 includes a rotor frame 141 and a permanent magnet 68.The rotor frame 141 has a thick portion 142, a center hole 143 in which bearings 49 and 50 are inserted, a cylindrical side wall 146 surrounding the armature 43, And a magnetic disk receiving portion 149.

In this case, the motor 130 first press-fits the armature 43 into the protruding wall 135, and then inserts the center shaft 132, in which the rotor 140 is provided on the free end 132d via the bear rigs 49 and 50 in advance, into the press-fitting hole 1
Press into 33 and assemble. A spacer 105 is interposed between the bearings 49 and 50.

Although the upper end of each shaft is a free end, it is also possible to apply a known technique of fixing the upper end to a disk upper frame (not shown) with a screw to prevent the shaft from tilting. In this case, a magnetic fluid seal is attached to the tip of the shaft on the lower surface side of the upper frame of the disk, so that the grease of the bearing can be prevented from scattering.

In the above embodiment, the drive motor is incorporated in the magnetic disk device. However, the same structure can be applied to an optical disk device or a magneto-optical disk device.

According to the above embodiments, all of the central axes 42, 82, 92, 10
Inner surface 41a, 81 of base 41,81,91,101,111,131 based on 2,112,132
a, 91a, 101a, 110a, and 131a are provided so as to protrude inward, so that in the assembly process of the motors 40, 80, 90, 100, 110, and 130, each component can be assembled without turning over the base, improving the efficiency of assembly work. I do. Also, since the base of the magnetic disk and the base of the drive motor are the same, the number of parts is reduced, the structure is simple and the size can be reduced, and the assembling accuracy is improved.

Further, when the central shaft is press-fitted as shown in FIGS. 6, 7, 8, and 10, the bases 81, 91, 101, 131 can be easily molded.

In addition, the pair of bearings 49, 50 are connected to the central shafts 42, 82, 92, 102,
With the free ends 42d, 82d, 92d, 102d, 112d, and 132d of 112 and 132, and the rotor frames 61 and 141 in a cantilever state, the armature
43 lead wires 47 can be easily pulled out.

When the preload is applied to the pair of bearings as described above, the rigidity of the bearings is increased, the runout accuracy is improved, and the rotational noise can be reduced.

As described above, according to the present invention, the center axis of the disk drive motor is projected inward on the inner surface of the base of the disk device,
A pair of rolling bearings is provided at the free end of the central shaft to support the rotor frame in a cantilevered state, so that each part can be incorporated sequentially from one side of the base, improving the assembly work efficiency and reducing the number of parts. As a result, the assembly accuracy is improved, and the structure is simple and the size can be reduced.

In the structure of the third aspect, in which the central shaft is mounted by press-fitting, a considerable press-fit length is required. However, there is an effect that the base can be easily formed and the cost can be reduced.

Further, according to the configuration of the present invention, the lead wires of the armature can be easily drawn out.

[Brief description of the drawings]

1 to 10 show an embodiment of the present invention, in which FIGS. 1 and 2 show a first embodiment, FIG. 1 is a longitudinal sectional view, and FIG. 3 and 4 show a second embodiment, FIG. 3 is a cross-sectional view in which a part is omitted, FIG. 4 is a partially enlarged view of FIG. 3, and FIG. FIG. 6 is a view of a structure in which spacers are omitted, FIG. 6 is a longitudinal sectional view in which a part is omitted in the third embodiment, FIG. 7 is a partially enlarged view of the fourth embodiment, FIG. 8 and FIG. FIG. 8 is a partially omitted longitudinal sectional view, FIG. 9 is a partially enlarged view of FIG. 8, and FIG. 10 is a partially omitted longitudinal sectional view of the sixth embodiment. FIG. 11 is a sectional view of a conventional example. A: magnetic disk device (disk device) B: magnetic disk (disk) C: air gap 40, 80, 90, 100, 110, 130 disk drive motor 41, 81, 91, 101, 111, 131 base 41a, 81a, 91a, 101a, 111a , 131a… Inner surface of base 42, 82, 92, 102, 112, 132… Central axis 42d, 82d, 92d, 102d, 112d, 132d… Free end of central axis 43… Armature 49, 50, 119, 120… Rolling bearing 60, 140… Rotors 61, 141 Cup-shaped rotor frames 66, 146 Cylindrical side walls 66a, 146a Inner surface of cylindrical side walls 68 Ring permanent magnets (permanent magnets) 69, 149 Magnetic disk receivers (disk receivers) 83, 93, 113 … Press-fitting parts 83a, 93a, 113a, 133 …… Press-fitting holes

Claims (3)

(57) [Claims] 1. A center shaft protruding inward from an inner surface of a base of a disk device, an armature concentrically disposed with respect to the center shaft, and a pair of rolling bearings at a free end of the center shaft. A cup-shaped rotor frame rotatably supported in a cantilever manner and having a cylindrical side wall and a disk receiving portion surrounding the outer periphery of the armature, and a gap fixed to an inner surface of the cylindrical side wall and an outer circumferential surface of the armature. A disk drive motor comprising: a permanent magnet facing through the disk drive; and being incorporated from one side of the disk drive. 2. The disk drive motor according to claim 1, wherein said center shaft is formed integrally with said base. 3. The disk drive motor according to claim 1, wherein said center shaft is press-fitted into said base.